Hi @Hoang Le ,
You are already familiar on how to read the data from the 'i7.csv' file using the readmatrix function in Matlab.
data = readmatrix('i7.csv');
Next, I set parameters by calculating the sample rate fs by multiplying the frequency f by 2. This is because the Nyquist theorem states that the sample rate should be at least twice the signal frequency. So, set the sample rate fs to 120 (adjusted for a 60Hz frequency) and the number of harmonics n to consider to 5.
fs = 120; % Adjusted sample rate for 60Hz frequency
n = 5; % Number of harmonics to consider
Afterwards, I calculate THD for multiple Ampere columns by iterating over columns 2 to 5 (assuming cur1 to cur5 are in columns 2 to 5) of the data matrix. So, for each column:
* It selects the current column data and preprocesses it to handle non-finite values using isfinite(signal).
* Calculates the THD value for the preprocessed signal using a custom thd function.
* Converts the THD value to a percentage using the formula THD_percentage = 10^(THD_dBc/20).
* Displays the THD value and THD percentage for the current column using disp.Then, finally understanding the Output:
* The output will show the THD value and THD percentage for each current column (cur1 to cur5).
* THD is a measure of the harmonic distortion present in a signal, expressed in decibels (dBc). A lower THD percentage indicates a cleaner signal with fewer harmonic distortions.For more information on thd function, please refer to
https://www.mathworks.com/help/signal/ref/thd.html
Please see attached results.
Hope this will help resolve your problem. Please let me know if you have any further questions.
